Method of and apparatus for producing sharp rontgen imagen



June 29 1926.

o. GOETZE METHOD OF AND APPARATUS FOR PRODUCING .SHARP RQ NTGEN IMAGESFiled August so, 1921 OTTU GOETZE J I June as, me

UNITED STATES 1,590,911 PATENT omen.

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llyinvention relate steim rovements gliirpRon 1112;1 5:393? t orebeenpropoeedtous'eRiin tgentubes with un- .sharpsourcesof rasfordiagnosticpurposes which require images. For this meethe BiintgenproJectionhasnotbeen by means of the rays which emanate from theanticathode at an angle of about 45 but by means ofrays which theanticathode in asuhstantially par- Therebyatleastinone direction thesource of rays appears to be shortenedtoav smallarea, andthetube u'hasmusled ,to thatof-a'tuhehavob ect of the resent improvements is to providea moth which makes use of a tube having anincandescent so cathode andanunsharp focal spot and yet produces which are sharp in anydi- Wi thisobject in view my invention consists in using a Riintgen tube having ant cathode producing .on I the anticathodea focal spot in the form'ot '2is a vertical section ofihe art of cent cathode and the anticathode, and

Fig. 8 is a similar section taken at right fernng nowto Fig. lit willbees-1 thatthe target or. hand providing of the rags and on the tobe'produced.

des position of the object and the elongated source of rays 4 acts wi alength tion-II or in a positionnear the use of a tube an unsharplsourcevery small. For taking a hotega h of a n ob'ect{for example of a Band on2 senll, 81 plate 5 I useonly such rays as are emitted substantially inthe direction of the l ne 4 which therefore form ve small angles withthe plane of the antics ode 3; For this purpose the object to beprojected on and the plate 5 are set inthe position I. When viewed fromthis point the line m pears to have been reducedto a very length ascompared to its actual length. If the actual length of the lineis L andthe rays neelt-infithewbject are at a median a (this Milli the anglebetween; the median ray and a 'ne perpendicular to the anticathode), the1 as seen from the point I appears'te be cos a. If 10 a 1s large,thisvalue is small, and the elongated source of light acts as a'focus in theform of a point. 4

In Fig. 15 the e a is about 70. It will be evident that this is alsotheanglewhich II the anticathode portion or source of rays 4' forms withthe longitudinal of the antica'thode (anode), which axis in this embodb'ment coincides with thelongitudinal of I j thetube,seeFigs.2and3. Th thele '0 which the anticathode surface 4 orms' with the axis of the tube,and therefore with the.

axis ofthe pencil of cathode rays, is an'acute 'angle'greater than theangle of 45 customarily employed hitherto,'and as a result of 86thisrnew arrangement, I obtain, in the equatorial zone of the tube, anapproximately point-like projection of theelongated spot upon theplane-in which;the image is roved The difierence between my um methodand the one now in use will derstood when setting the object and thesensitized late 5 inthe 'tion II. Inthis P P M L cos B. The 1e B isabout 15. Them"- fore with the ob ect and plate in the theretoreproductions can not be had, and when seen frompoint II the source ofrays 4 will appear as a lineof substantial length and fromwhich onlyanunsharp can be had. Therefore, my improved methedpei'mits of rays inthe form of a band loo.

purposes for roducing sharp Rontgen images, the resu t being the same asthat of a tube having a shar source of rays.

In Figs. 2 and 3 have shown a preferred exam le of the essential partsof a Riintgen. tu e having an incandescent cathode and collecting means(Coolidgetube), which in a simple way ermits\the production of'a sourceof rays in the form of a band. For this purpose the incandescent wire 1is not disposed in the usual way and in the formof a coil, but I preferto arrange the same along a straight'lineand in one direction, and it issurrounded by a collector 2, havin the form of an elon gated box: Bymeans of this collector the cathode rays are distributed over a spacethe cross-section ofwhich is likewise in the form of a narrow rectangle,so that-the rays produce on the anticathode 3a focal spot 4 in the formof a rectangle.

i It will be noted thatin the specific embodiment illustrated, theheated filament or.

cathode extends in a substantially straight line located in aplaneperpendicular to the plane of the anticathode, and. that thecathode and the anticathode converge in such perpendicular plane. Itwill be further noted the collector co-operating with the said cathodeis in the form of an elongated box open toward the anticathode,'thelonfitudinal axis of said box being parallel tot at of the cathode.

In a Rontgen tube with incandescent cathodeprovided with an intermediateelectrode the focal spot in the form of a band is produced in a simpleway by forming the intermediate electrode with an opening] in the formof a rectangle for the passage.

of the rays therethrough.

To permit the use of the Rentgen tube with incandescent cathode thedirection of the linear focus should be such that it can be put to usewithout materially changing the usual tripods. For this reason all the jparts projecting from the tube are arranged in the usual way, and insome cases the anti-..

cathode must be inclined relatively to the axis of the tube at a greaterangle than is usual in other tubes, as will be understood from aninspection of-the drawing.-

I claim:

' 1. The herein desci'ibedmethod of pro ducmg Rentgen'images whichconsists incausing emission of.R6ntgen rays from. an elongated focalspot,and using, for the production of the images, the rays emanatingfrom said spotsubstantially in the direction of the length of the spot-2. .The method herein described of proof said target.

ducing Rontgen images, which consists in causing the emission of Rentgenrays from a focal spot havin a length great as compared with its width,and producing an image from such of the rays emanating from said spot asare projected therefrom in a direction nearly coincidin with the generaldirection of the spot. a

3. An X-ray tube having a plane'anticathode, an incandescent cathodeconstructed to produce, in conjunction with said anti- *to less thanhalf the actual length of said length 0 said focal target, said meanscomprising a plane target shaped as a narrow band, a cathode consistingof a straight incandescent filament, said target and filament lying in acommon plane at an angle of less than 45 degrees to each other, and acollector partially surrounding the cathode.

. 5. Inan X-ray tube, means for obtaining, in the equatorial zone of thetube, a pro jection of the target which is foreshortened to less thanhalf the actual length of sa d target, said means comprising a target 1nthe form of a narrow band, a cathode con sistingof an incandescentfilament extending in a substantially straight line, said target andcathode bein positioned in a common plane at an ang e of less than45degrees'to each other, and a collector partially surrounding thecathode.

" 6. An X-raytube having a plane target in the form of a narrow band, anelongated incandescent cathode, said target and cathode being disposedina common plane, a

collector associated with said cathede the active surface of said targetbeing inclined at an angle of more than 45' degrees to the longitudinalaxis of the tube, so as to obtain, in the equatorial zone of the tube, aprojection of "the target which is foreshortened to less than half theactual length In testimony signature.

whereof I hereunto afiix my.

m. o'i'ro GoE'rzn.

